The present disclosure relates to the field of control devices, and more particularly to the field of contactless control devices, in particular for a washroom fixture.
It is known to fit washroom facilities, such as wash basins, faucets, urinals, showers, hand dryers, soap dispensers, . . . with control devices that enable them to be operated without requiring the user to make contact, in particular hand contact. Such control devices present the advantage of keeping the washroom fixture clean since it is not touched by the user, thereby limiting the development and the transmission of germs or bacteria. Furthermore, they also make it possible to limit the quantity of water or of electricity that is consumed by the washroom fixture, since it runs only in the presence of a user, and stops when the user moves away and ceases to use it.
It is thus known to fit washroom facilities with contactless control devices, using infrared emitters and sensors. The washroom fixture is controlled as a function of the infrared intensity measured by the sensor. More precisely, the control device causes the washroom fixture to operate when the infrared intensity detected by the sensor increases, which corresponds to a user being present in the proximity of the detector.
An example of such a device is described in particular in application FR 2 761 446 A1. In that document, one of the infrared detectors is mounted at the end of the faucet and is directed towards the bowl into which the faucet delivers water: the infrared intensity measured by the sensor in the presence or absence of a user is thus known and easy to set. Nevertheless, the detector must be mounted facing a surface that is unchanging and known.
There also exist infrared detectors that serve to detect the presence of a user without needing to be mounted facing a determined surface. Such detectors are background-canceling sensors that make it possible, in particular by means of a system of lenses and/or an array of detectors, to be more accurate than standard infrared sensors in estimating the distance between a detector and the user. Such background-canceling sensors can thus be mounted somewhere other than at the free end of the faucet, e.g. at the base of the faucet.
Nevertheless, when a background-canceling detector is to be installed in a room having mirrors or ceramics, it is often necessary to perform an operation of setting up the sensor so that it can take account of interfering reflections in order to obtain the desired operation.